導語:英語單詞as可作關係代詞,下面小編講解as可以引導的定語從句,歡迎參考。
as作關係代詞時,引導定語從句在從句中充當主語、賓語、介詞賓語或表語,既可以指人,也可以指物。
(1)as引導定語從句時,有如下結構:“the same …as”,“such …as”, “as…as”“so many (much, few, little)…as”,譯作“像……一樣的人(或物)”。例如:
This is such an easy novel as you can read.
這本小說很容易,你能讀得懂。
They have never read so many books as I read last year.
他們從來都沒有讀過像我去年讀過的那些書。
(2)as單獨引導定語從句時,修飾整個主句或主句中的一部分,可以放在句首、句中或句末。當as在從句中作主語時,從句的謂語通常是被動語態或系表結構;as在從句中作賓語時,從句的謂語常用“情態動詞+動詞原形”構成。常見的結構如下:
as is known to all 眾所周知
as has been said above 如上所述
as was expected 正如預料的那樣
as has been pointed out 正如指出的那樣
as we all can see (know, hear)正如大家看到的(知道的、聽到的)那樣。例如:
As is known to everybody, the moon travels round the earth once every month.
眾所周知,月球每個月繞地球轉一週。
引導限制性定語從句:
用在 such, same, as 等之後,引導限制性定語從句。如:
I live in the same place as Tom does. 我和湯姆住在同處。
He’s not such a fool as he looks. 他並不像看上去的那樣愚蠢。
He smokes as expensive a cigarette as he can afford. 他抽一種他買得起的最貴的煙。
引導非限制性定語從句:
(2) 單獨用作關係代詞,引導非限制性定語從句,可放在主句之前、之後或中間,且主從句之間一般要用逗號隔開。如:
As was expected, he succeeded at last. 正如我們所料,他終於成功了。
I had coffee after dinner, as is my usual practice. 我飯後喝咖啡,這是我的習慣。
Freddie, as might be expected, was attending the conference. 弗雷迪在參加會議,這是可以預料到的。
as與which的用法區別:
① 引導限制性定語從句的區別:as用作關係代詞引導限制性定語從句時,它通常只用於 such, same, as 等之後,而which 用作關係代詞引導限制性定語從句時,則用於除 such, same, as 之外的`其他結構。
② 引導非限制性定語從句的區別:which引導非限制性定語從句時,通常只能位於主句後,而as引導的非限制性定語從句位於主句之前、之後或中間。
根據從句謂語動詞的特點來看,as在定語從句中作主語時,從句謂語通常要有be或別的系動詞,但which不受此限制。如:
Li Ming was late, which (=and this) made Mr. Zhang very angry. 李明遲到了,這件事使張先生非常生氣。(不可用as)
根據句意的邏輯性來看,as引導的定語從句只表示一個眾所周知或意料之中的事,但which不受此限制。如:
He married her, as [which] was natural. 他和她結婚了,這是很自然的。
He married her, which was unexpected. 他和她結婚了,這是出乎意料的。(不可用as)